1. Field
One or more embodiments described herein relate to a display device.
2. Description of the Related Art
Melatonin is a hormone that influences biorhythms (such as circadian rhythm and annual rhythm in reproductive activity) by sensing photoperiods. The secretion of melatonin is controlled by melatonin control cells found in human eyes.
When melatonin control cells absorb light of a melatonin production inhibition wavelength of 446 nm to 477 nm having a peak of 464 nm in sunlight, the melatonin control cell suppresses secretion of melatonin. Thus, in daytime, during which light of the melatonin production inhibition wavelength is irradiated, the production of melatonin is suppressed by the melatonin control cells. As a result, the human body feels less tired. Conversely, in nighttime, during which light of the melatonin production inhibition wavelength is not irradiated, the production of melatonin is not suppressed. As a result, the human body feels tired and needs sleep.
Melatonin affects other biological functions. For example, melatonin influences metabolism related to blood flow, hormone control, and removal of bodily waste.
These days, people tend to stay indoors more during the day, and thus have less chance of being exposed to sunlight including a melatonin production inhibition wavelength. The human body, therefore, may not be able to function under optimum conditions. Also, the production of melatonin may be suppressed late into the night because of watching television or other lighting effects. Consequently, people may not have sound sleep. In an attempt to obtain improved sleep, people may take chemically composed melatonin medications or supplements. However, these medications or supplements have been shown to have deleterious effects.